Piston pump

ABSTRACT

A piston pump in which the cylinder head encloses the valve housing in such a manner that the delivery valve chamber which is located behind the delivery valve, as seen in the direction of flow of the fluid conveyed through the pump, needs to be sealed relative to the outside only by a single high-pressure gasket which is provided between this valve chamber and the intake line.

I United States Patent [151 3, Fries [451 Nov. 14, 1972 1 PISTON PUMP3,106,169 10/1963 Prosser et al. ..l37/5l2 X 3,309,013 3/1967 Bauer..l37/5l6.l3 X [72] Germany 3,309,014 3/1967 Bauer ..l37/516.13 x [73]Assignee: Pumpenhbrlk Urach, Urach, Ger- 3,508,849 4/1970 Weber 137/516. 13 X many 3,526,246 9/1970 Leitgeb ..l37/512.3 [22] led: 1969Primary Examiner-Samuel B. Rothberg [21] App]. No.: 857,373 AssistantExaminer-David J. Zobkiw Attorney-Michael S. Striker [30] ForeignApplication Prlority Data 57 ABSTRACT Sept. 17, 1968 Germany ..P 17 28243.8 A piston pump in which the cylinder head encloses the valvehousing in such a manner that the delivery valve UQS- Cl. 12-5, climberwhich is the delivcry valve as 137516-23. 417/567 seen in the directionof flow of the fluid conveyed Int. through the pump, needs to berelative to [ha outside only by a single high-pressure gasket which isl37/516.l1,5 16 .1 3, S l l 5;4l7/567,5 9 provided between this valvechamber and the intake line. 56 Ref Cited 10 Clalms, 5 Drawing figuresUNITED STATES PATENTS 1125,899 11/1965 Waibel ..137/5l6.15 X

Pistols PUMP The present invention relates to a piston pump especiallyfor high pressures which comprises a valve hous ing which is insertedinto the cylinder head, and a delivery-valve chamber which is locatedbehind the delivery valve, as seen in the direction of flow of the fluidconveyed through the pump. If such a fluid is to be conveyed under highpressures, for example, up to 500 or 1,000 atm., or if it is of aparticular type, for example, a radioactive fluid, it is an absolutenecessity that the pump housing will be tightly sealed toward theoutside.

It is therefore an object of the present invention to provide a pistonpump which for sealing it so tightly and fully reliable relative to theoutside requires only very simple means and at the fewest possiblepoints of the pump.

One important feature of the invention therefore essentially consists inproviding only a single high-pressure gasket between the cylinder headand the valve housing for sealing the delivery valve chamber relative tothe intake line by enclosing the delivery valve chamber within thecylinder head without any seams toward the outside at least up to theintake line which is likewise enclosed by the cylinder head.

By designing the pump in this manner there is no longer any need toprovide any further means for sealing the delivery valve chamber withinthe housing which would otherwise be required under the high pressureswhich are to produced by such a pump. According to the invention it istherefore only necessary to seal the delivery valve chamber relative tothe intake chamber. However, since this single high-pressure gasket isan internal gasket, any leakage of the fluid under pressure from thedelivery valve chamber to the intake chamber is practically without anyconsequence since the pressures cannot escape toward the outside and thefluid which might leak through to the intake chamber will again be takenup by the fluid passing through this chamber and be passed once more tothe delivery valve chamber.

Aside from this single internal high-pressure gasket, it is anotherfeature of the invention to provide only low-pressure gaskets foreffecting the sealing action toward the outside. This applies especiallyif the cylinder housing and the valve housing are integrally connectedto each other or if the cylinder housing and the cylinder head arewelded together subsequent to their installation. If, however, forexample, for reasons of installation, a valve housing is provided whichconsists of several parts, an additional high-pressure gasket may beprovided for sealing the pump chamber relative to the outside.

Another object of the invention consists in providing an especiallyadvantageous arrangement of the delivery valve means and/or the intakevalve means on the valve housing which may, for example, also be madeintegral with the cylinder housing of the machine, and which arrangementpermits the valve means to be easily installed. A further feature of theinvention consists in the particular design and construction of thesevalve means and especially in their particular combination with therequired sealing means.

These and additional objects, features and advantages of the presentinvention will become further apparent from the following detaileddescription thereof which is to be read with reference to theaccompanying drawings, in which FIG. 1 shows an axial section of thepump chamber and the associated parts of a first embodiment of themachine according to the invention;

FIG. 1b is a partial axial cross-section of a slightly modifiedconstruction;

FIG. 2 shows a cross section which is taken along the line 2-2 of FIG.1;

FIG. 3 shows an axial section similar to that according to FIG. 1 of asecond embodiment of the invention; while FIG. 4 shows a similar axialsection of a third embodiment of the invention.

In the drawings, FIG. 1 illustrates generally a first embodiment of theinvention in which the cylinder housing is designated by the numeral 10and the cylinder head by the numeral 11. At the inside of the cylinderhousing 10 the piston 12 is movable back and forth in the direction ofthe arrows x, and x,, carrying out its intake stroke in the direction x,and its compression stroke in the direction x,.

Cylinder head 11 is provided with a socket bore 13 through the open endof which the valve housing 14 is inserted so as to fit tightly into thisbore. The fluid, especially a liquid, which is to be conveyed by thepump is conducted through one or more intake channels 15, which may alsobe combined to form an annular channel, for example, the channel 16, tobores 17 which lead to an intake valve 18 which in this embodiment ofthe invention is provided in the form of an annular valve which is actedupon by a spring 20 which tends to press it upon a seat 18a in the valvehousing 14 so as to close the intake channels 17 relative to the pumpchamber 19. The rear end of spring 20 is supported on the flange of acap-shaped member 21 which is connected by a valve rod 22 to thedelivery valve 23 which by the action of spring 20 is adapted to bepressed upon a seat 24 at the opposite end of the valve housing 14. Ifdesired, the force of spring 20 may be increased by an additional spring25 which acts directly upon the delivery valve 23. The intake valve 18and the delivery valve 23 are provided with radial webs 27 and 28 forguiding them within a central bore 26 of valve housing 14.

After the insertion of the valve housing 14 into the bore 13 of thecylinder head 11, the latter tightly encloses the valve housing in sucha manner that the delivery valve chamber 29 which is located behind thedelivery valve 23, as seen in the direction of flow y,, y,, y, of thefluid to be conveyed, is not connected to the outside by any gap withinthe cylinder head 11 which would have to be sealed. The only gapadjacent to the valve chamber 29 is a gap 30 between this valve chamberand the intake channels 15, I6, 17, and this gap 30 is tightly sealed byan internal annular highpressure gasket 31.

In FIG. 1 which is called FIG. la, the valve housing 14 forms an elementseparate from the cylinder housing 10. Therefore, an additionalhigh-pressure gasket 32 is inserted in this case between the valvehousing 14 and the cylinder housing 10 for sealing the pump chamber 19toward the outside and another gasket 33 for sealing the intake line 15,16, 17 toward the outside.

This gasket 33, however, only has to be a simple low pressure gasket toproduce a secure sealing effect.

In FIG. 1a, there is no need for the high-pressure gasket 32 since thecylinder housing and the cylinder head 11 are welded together asindicated by the welded joint 34. Such a welded joint now permits theparts 10 and 11 to be absolutely sealed toward the outside as if theywere integral with each other. This welded joint may also be provided inthe form of a bead, as indicated in FIG. 1b, which may again be removedwithout any great difficulties if it becomes necessary to replace anyparts at the inside of the machine. It is necessary to provide for thispossibility especially if very high pressures are produced by the pumpand particularly insofar as the valve housing 14 is concerned sinceafter a certain period of operation of the pump this valve housing hasthe tendency to be damaged under the severe alternating stresses towhich it is continuously subjected.

In the embodiment as shown in FIG. 1 and even in the welded embodimentas shown in FIG. 10 it is advisable to secure the cylinder head 11 andthe cylinder housing 10 to each other by traction bolts, as indicated bythe dot-and-dash line 35.

FIG. 3 illustrates a second main embodiment of the invention in whichthe parts are similar to those as shown in FIG. 1 are designated by thesame numerals which, however, are raised by 100 over those in FIG. 1.The most important difference between these two embodiments is the factthat in the embodiment according to FIG. 3 the intake valves 118 arelocated within the valve housing 1 14. Preferably a plurality of theseintake valves I18 extend in radial directions within the valve housing114 and at equal peripheral distances from each other within radialapertures and they are made of such dimensions that they may be insertedthrough the central bore 126 of valve housing 114 into these aperturesand then be placed on their seats 118a. Springs 120, for example,traction springs, the radially outer ends of which may be hooked intotransverse brackets 121 tend to maintain the intake valves 118 on theirseats 1184 within the radial apertures. The delivery valve 123 is alsoin this case pressed upon its seat 124, for example, by a spring 125.

Since the intake valves 118 may be inserted through the bore 126, thevalve housing 114 and the cylinder housing 110 may together form asingle integral element. Aside from the high-pressure gasket 131 betweenthe delivery valve chamber 129 and the intake line 115, it is in thiscase only necessary to provide a low-pressure gasket 133. If, however,the valve housing 114 should be replaceable independently of thecylinder housing 110, an additional high-pressure gasket 132 may also inthis case be provided. This gasket may, however, also be omitted if thetwo parts 110 and 114 are tightly secured to each other by a weldedjoint.

FIG. 4 illustrates a third main embodiment of the invention in which theparts which are similar to those of the first embodiment as shown inFIG. 1 are likewise designated by the same numerals which, however, areraised by 200 over those in FIG. 1. This embodiment differs from that asshown in FIG. 2 primarily by being provided with an axially movableannular intake valve 218 in place of the radially extending intakevalves 1 18.

This valve 218 which surrounds the valve housing 214 forms a disk and ispressed by a coil spring 220 upon its seat 218a which forms the bottomof a ring 236 of a substantially U-shaped cross section which is pressedby an annular nut 237 in the direction toward a shoulder on the cylinderhousing 210 which carries a gasket ring 238 against which the open sideof ring 236 is pressed. The annular nut 237 and the bottom of ring 236upon which the valve disk 218 engages are provided with substantiallycorresponding ducts leading to the intake line 215. At the other side ofvalve disk 218, the inner side of ring 236 is connected by apertures inthe gasket ring 238 and by channels 239 extending through the wall ofthe cylinder housing 210 with the pump chamber 219 which, in turn, isconnected by the central bore 226 with the delivery valve chamber 229 inthe cylinder head 211 of the machine. When the delivery valve 223 ispressed by spring 225 upon its seat 224 at the end of bore 226, it sealsthis end tightly relative to the delivery valve chamber 229.

This valve chamber 229 is again sealed relative to the intake line 215by a high-pressure gasket 231. Although in this particular case theannular gasket 238 is also a high-pressure gasket, it merely forms aninternal sealing element which does not seal the pump chamber 218 fromthe outside buy only from the intake line 215.

In both embodiments of the invention as illustrated in FIGS. 3 and 4,the valve housing 114 or 214 is integrally combined with the cylinderhousing or 210, respectively. Therefore, aside from an internalhigh-pressure gasket 131 or 231 and the additional internalhigh-pressure gasket 238 according to FIG. 4, there is only a singlelow-pressure gasket 133 or 233 required for sealing the intake line or215 relative to the outside. If, however, the cylinder housing 110 or210 and the valve housing 114 or 214 are desired to form two separateelements so as to permit the valve housing to be removable from themachine independently of the cylinder housing, the associated housingsmay either be sealed relative to each other by a highpressure gasket inthe manner as shown in FIG. la or they may be connected to each other bya welded joint in the manner as shown in FIG. 1b.

Although my invention has been illustrated and described with referenceto the preferred embodiments thereof, I wish to have it understood thatit is in no way limited to the details of such embodiments but iscapable of numerous modifications within the scope of the appendedclaims.

Having thus fully disclosed my invention, what I claim is:

1. A piston pump, especially for conveying fluid under high pressure,comprising, in combination, a one-piece cylinder head being fonned witha blind bore having a large-diameter bore portion at the open end and asmall-diameter bore portion at the closed end thereof and forming ashoulder face between said open and said closed end, said small-diameterbore portion constituting a delivery chamber; a valve housing located insaid large-diameter bore portion and having a maximum diametersubstantially equal to that of said large-diameter bore portion so as tobe insertable and removable through said open end of said bore, saidvalve housing having at one end an end face facing said shoulder face ofsaid cylinder head; a cylinder housing connected to the other end ofsaid valve housing, said valve housing and said cylinder housingdefining a pump chamber; intake passage means extending through saidcylinder head and said valve housing and communicating with said pumpchamber; intake valve means for controlling flow of fluid from saidintake passage means into said pump chamber; further passage meansextending through said valve housing and providing communication betweensaid pump chamber and said delivery chamber; delivery valve means forcontrolling flow of fluid from said pump chamber through said furtherpassage means into said delivery chamber, said intake valve means andsaid delivery valve means are respectively disposed at opposite ends ofsaid valve housing, respectively facing said pump chamber and saiddelivery chamber, and are adapted to open in opposite directions to eachother; spring means having one end acting upon said intake valve meansand tending to maintain the same in closed position; means forsupporting the other end of said spring means; an element connectingsaid supporting means substantially rigidly to said delivery valve meansso that said spring means also tend to maintain said delivery valvemeans in closed position; delivery passage means communicating with saiddelivery chamber downstream of said delivery valve means; and ahigh-pressure gasket between said faces to prevent escape of fluid fromsaid delivery chamber between said faces.

2. A piston pump as defined in claim 1, and further comprising at leastone annular low-pressure gasket surrounding said valve housing in theregion of said open end of said bore in said cylinder head.

3. A piston pump as defined in claim 1, wherein said valve housing andsaid cylinder housing have end surfaces facing each other and includingmeans for connecting said housings to each other and an otherhighpressure gasket between said end surfaces and sealing said pumpchamber against the outer atmosphere.

4. A piston pump as defined in claim 1, wherein said delivery valvemeans is located at one end of said further passage means and saidintake valve means is annular and surrounds the other end of saidfurther passage means, said intake passage means through said valvehousing being located radially outwardly of said further passage means.

5. In a piston pump, a combination comprising a body means defining apump chamber; fluid intake passage means in said body meanscommunicating with said pump chamber for feeding fluid into saidchamber;

a delivery chamber in said body means; further passage means in saidbody means providing communication between said pump chamber and saiddelivery chamber; intake valve means movable between open and closedpositions for controlling flow of fluid from said fluid intake passagemeans to said pump chamber; delivery valve means movable between openand closed position for controlling flow of pressurized fluid from saidpump chamber to said delivery chamber; a spring engaging with one endone of said valve means and tending to maintain the latter in saidclosed position; and means supporting the other end of said spring andconnected to the other of said valve means so that said spring tends tohold also the other of said valve means in closed ition.

s. A combina r i as defined in claim 5, wherein said intake valve meansand said delivery valve means are coaxially arranged, said one of saidvalve means being an annular valve and said supporting and connectingmeans comprises a valve stem on the other of said valve means projectingwith a portion thereof through and beyond said annular valve and anabutment on said portion of said valve stem against which the other endof said spring abuts.

7. A combination as defined in claim 6, wherein said one valve meansconstitutes said inlet valve means and said other valve meansconstitutes said delivery valve means.

8. A combination as defined in claim 7, said body means comprising acylinder head formed with a blind bore, a valve housing in said blindbore, a cylinder housing connected to one end of said valve housingwhich faces away from the closed end of said blind bore and definingwith said valve housing said pumps chamber, said further passage meanscommunicating at one end with said pump chamber and extending throughsaid valve housing, said intake passage means surrounding said one endof said further passage means, said one means being located at said oneend of said valve housing and said other valve means at the other endthereof, said valve stem extending through said further passage means.

9. A combination as defined in claim 5, said body means including avalve housing through which said fluid intake passage means and saidfurther passage means extend, and valve seats for said valve meansprovided on opposite ends of said valve housing.

10. A combination as defined in claim 9, and including an additionalspring pressing said delivery valve means against its valve seat.

1. A piston pump, especially for conveying fluid under high pressure,comprising, in combination, a one-piece cylinder head being formed witha blind bore having a large-diameter bore portion at the open end and asmall-diameter bore portion at the closed end thereof and forming ashoulder face between said open and said closed end, said small-diameterbore portion constituting a delivery chamber; a valve housing located insaid large-diameter bore portion and having a maximum diametersubstantially equal to that of said large-diameter bore portion so as tobe insertable and removable through said open end of said bore, saidvalve housing having at one end an end face facing said shoulder face ofsaid cylinder head; a cylinder housing connected to the other end ofsaid valve housing, said valve housing and said cylinder housingdefining a pump chamber; intake passage means extending through saidcylinder head and said valve housing and communicating with said pumpchamber; intake valve means for controlling flow of fluid from saidintake passage means into said pump chamber; further passage meansextending through said valve housing and providing communication betweensaid pump chamber and said delivery chamber; delivery valve means forcontrolling flow of fluid from said pump chamber through said furtherpassage means into said delivery chamber, said intake valve means andsaid delivery valve means are respectively disposed at opposite ends ofsaid valve housing, respectively facing said pump chamber and saiddelivery chamber, and are adapted to open in opposite directions to eachother; spring means having one end acting upon said intake valve meansand tending to maintain the same in closed position; means forsupporting the other end of said spring means; an element connectingsaid supporting means substantially rigidly to said delivery valve meansso that said spring means also tend to maintain said delivery valvemeans in closed position; delivery passage means communicating with saiddelivery chamber downstream of said delivery valve means; and ahigh-pressure gasket between said faces to prevent escape of fluid fromsaid delivery chamber between said faces.
 2. A piston pump as defined inclaim 1, and further comprising at least one annular low-pressure gasketsurrounding said valve housing in the region of said opeN end of saidbore in said cylinder head.
 3. A piston pump as defined in claim 1,wherein said valve housing and said cylinder housing have end surfacesfacing each other and including means for connecting said housings toeach other and an other high-pressure gasket between said end surfacesand sealing said pump chamber against the outer atmosphere.
 4. A pistonpump as defined in claim 1, wherein said delivery valve means is locatedat one end of said further passage means and said intake valve means isannular and surrounds the other end of said further passage means, saidintake passage means through said valve housing being located radiallyoutwardly of said further passage means.
 5. In a piston pump, acombination comprising a body means defining a pump chamber; fluidintake passage means in said body means communicating with said pumpchamber for feeding fluid into said chamber; a delivery chamber in saidbody means; further passage means in said body means providingcommunication between said pump chamber and said delivery chamber;intake valve means movable between open and closed positions forcontrolling flow of fluid from said fluid intake passage means to saidpump chamber; delivery valve means movable between open and closedposition for controlling flow of pressurized fluid from said pumpchamber to said delivery chamber; a spring engaging with one end one ofsaid valve means and tending to maintain the latter in said closedposition; and means supporting the other end of said spring andconnected to the other of said valve means so that said spring tends tohold also the other of said valve means in closed position.
 6. Acombination as defined in claim 5, wherein said intake valve means andsaid delivery valve means are coaxially arranged, said one of said valvemeans being an annular valve and said supporting and connecting meanscomprises a valve stem on the other of said valve means projecting witha portion thereof through and beyond said annular valve and an abutmenton said portion of said valve stem against which the other end of saidspring abuts.
 7. A combination as defined in claim 6, wherein said onevalve means constitutes said inlet valve means and said other valvemeans constitutes said delivery valve means.
 8. A combination as definedin claim 7, said body means comprising a cylinder head formed with ablind bore, a valve housing in said blind bore, a cylinder housingconnected to one end of said valve housing which faces away from theclosed end of said blind bore and defining with said valve housing saidpumps chamber, said further passage means communicating at one end withsaid pump chamber and extending through said valve housing, said intakepassage means surrounding said one end of said further passage means,said one means being located at said one end of said valve housing andsaid other valve means at the other end thereof, said valve stemextending through said further passage means.
 9. A combination asdefined in claim 5, said body means including a valve housing throughwhich said fluid intake passage means and said further passage meansextend, and valve seats for said valve means provided on opposite endsof said valve housing.
 10. A combination as defined in claim 9, andincluding an additional spring pressing said delivery valve meansagainst its valve seat.